www.venus.uvic.ca venus@uvic.ca

Summer 2010

The Ocean Online, Real time, Any time

VENUS Data in Your Hand

• VENUS Website Goes Mobile

VENUS data are now available in the palm of your hand. View the VENUS website in a mobile-friendly version on your iPhone, iPod Touch, Blackberry, or other mobile device. The Live Data Applets now use Java and are compatible with iPhone OS. Watch for more to come as we review all of our content for a better mobile experience. If you're on a data plan, be aware that the website is still bandwidth intensive.

• Live Data on Your iPhone

Live VENUS data are also in a free iPhone App from the Northwest Association of Networked Ocean Observing System (NANOOS). The NANOOS Visualization System (NVS) makes it possible for users to access and compare live ocean data from multiple sites in the Northwest, including the VENUS subsea laboratories, surface buoys, and coastal stations. Get it in the App Store: http://itunes.apple.com/ca/app/nvs/id373563865?mt=8.

Now that the cabled infrastructure on the seabed is well established and robust, the VENUS Facility is entering a new growth phase following a successful grant award through the Canada Foundation for Innovation. Over the next 4 years VENUS will grow: • Additional seafloor sensors in moveable ‘modules’; • Remote and direct measurements at the surface (HF Radar and

instrumented Ferries); • Interactive profiling of the water column in Saanich Inlet (Profiler); • Remote measurements made by mobile assets (Gliders and an AUV); • New data products and presentations. In Saanich Inlet, the Facility will install a large powered buoy mid Inlet, cabled back to the subsea Node. On the buoy a sophisticated winching system will allow hourly profiles of the water column. The modular sys-tem will support more than 20 sensors at any given time. The Inlet is an ideal location for biogeochemical especially in the circumstance of growing hypoxia in the ocean. The Strait of Georgia is the second busiest waterway in North America, and is also home to the outflow of a major salmon spawning river. The VENUS cabled array in the Strait supports real-time science on whale

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Building for New Research on VENUS

Vancouver

Victoria

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vocalizations, sediment transport, salmon abun-dance and the stability of the delta slope. We will expand VENUS capabi-lity with HF radar anten-nae, providing surface current and wave infor-mation to scientists, shipping, rescue coordina-tion agencies, among others. Furthermore, the Facility will instrument several Ferries to enable the measurement of oceanic and meteorological surface conditions in the Strait. These data, as with the radar information, will be transmitted back to the database made available online.

For the first time, the Facility will deploy mobile assets to allow scientists to sample in ways, places and conditions that would otherwise not be possible. To obtain water column properties in the tidally dynamic Strait, ocean gliders will gather data such as temperature, salinity, oxygen, chlorophyll-A and turbidity as they travel from surface to seabed.

In collaboration with the Ocean Technology Laboratory at UVic, the Facility will also offer scientists access to an AUV. The vehicle will undergo a retrofit to enable additional sensor technologies and capabilities, including modes for seabed tracking and profiling.

Five specialized platforms will support research on seafloor processes by configuration to suit evolving experiments anywhere within the Facility. Each platform will have up to 12 instruments focused on a study theme. Cameras (Near-Infra-Red, Acoustic, Digital), current and turbulence sensors, chemical and sediment sen-sors etc. will be used, often in novel ways and applications. These sub-sea Laboratories will be unique in scope, flexibility, and access.

All of these systems are reliant on a complex data management system. The existing infra-structure is now well understood and managed. The arrival of these new technologies and data will undoubtedly introduce associated challenges, both at the outset and operationally over the years. Perhaps the greatest challenge for the science community at large will be the synthesis and integration of all of this information derived from different sources.

VENUS recognizes this challenge. Ultimately the goal is to become an integrated observing system that serves focused studies on the seabed but also encapsulates all the sensing information to provide over-arching forecasts of the state of the coast.

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VENUS has several instruments designed for measuring ocean currents. The Nortek AquaDopp and the RDI acoustic Doppler current profilers (ADCP) measure the mean currents near the bottom and throughout the water column, respec-

tively. Two specialized instruments where deployed on the DDL recently to measure water velocities at both small scales and fast temporal resolu-tion. They are a Nortek Vector acoustic Doppler velocimeter (ADV) and a Vectrino ADV. These very high-frequency (6 MHz) active bi-static Dop-pler systems transmit from a single central transducer and receive the Doppler shifted echo-return from a common volume at three radially separated receivers. The effective sample rate can be adjusted between 1 to 64 Hz. In addition to the raw velocities from the three beams, the instrument also reports the compass and tilts for conversion to Earth

NORTEK Vector - Measuring Turbulence. Richard Dewey (VENUS) and Gwyn Lintern (NRCan)

Figure 1. Time series of the turbulent dissipation rate (ε) in [W/kg] as de-termined from a fit of the Nasmyth universal spectrum to 5 minute run-ning segments of the Nortek Vector w’ data (top). Also shown are the raw 4Hz velocities (middle) and estimates of the bottom friction velocity (u*) assuming a local production/dissipation balance in the constant stress layer (bottom).

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coordinate velocities. These high-resolution, fast data generating instruments are ideally suited for deployment on a cabled observatory. Recently, Richard Dewey was invited to give a presentation at the annual Nor-tek Users Workshop in Seattle WA (May 19-21, 2010). He presented some pre-liminary analysis of the Vector data collected on the Delta Dynamics Labora-tory between February 26 and March 11, 2010. Through spectral analysis, time series of the turbulent dissipation rate and the internal Reynolds stress were quantified, along with the friction velocity associated with the bottom stress (Figure 1). These are all critical quantities associated with the local dynamics, the flux of both momentum and chemical quantities, and in determining the likelihood of sediment re-suspension, respectively. Although this is not the first time such quantities have been calculated from ADV devices, it does demonstrate the utility of a cabled observatory, with unlimited power and data transfer for making continuous, long-term high-resolution velocimeter measurements and assessing the nature of the turbulent ocean, for dynamics, mixing, and sediment transport research.

Photo: Mei Sato, PhD Student (University of Victoria) prepares the Nortek Vector for deployment in the Fraser River Delta study area.

In February 2010, VENUS added another seafloor camera to its network. Called “SoG Webcam”, the new camera is installed on a platform linked to the Strait of Georgia Central Node. Streaming live video from 300m, the camera offers a unique opportunity to examine a benthic marine habitat in its natural state. Current knowledge of the deep water denizens of Strait of Georgia is pri-marily based on captured animals or moving ROV surveys. By recording animals on a regular basis in one location, researchers examine the effects of currents and other parameters measured on the Instrument Platform. This rare footage provides detailed information on the behaviour of species for which little is known. For example, the shortspine thornyheads, Sebastolobus alascanus, are believed to be a solitary species yet we often see more than one. Check the camera schedule and join live observations at http://www.venus.uvic.ca/?page_id=3805.

Live Video from the Strait of Georgia is On

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VENUS - Victoria Experimental Network Under the Sea

Phone: 250-472-5366 Fax: 250-472-5370

A sediment trap on the VENUS Instrument Platform in Saanich Inlet has collected sediment samples nearly continuously since November 2007 at sampling intervals ranging from 12 hours to 19.5 days. Our research project monitors high-resolution changes in seasonal and annual phytoplankton pro-duction in Saanich Inlet. For my Honours thesis, under the supervision of Dr. Vera Pospelova, I investigated the relationship between dinoflagellate pro-duction, diatom production (estimated by biogenic silica flux) and environ-mental parameters. Dinoflagellates, a diverse group of phytoplankton in coastal waters, are impor-

tant primary producers at the base of the marine food chain. Many species of dinoflagellates produce resting cysts that sink to the sea-floor and are able to sur-vive unfavourable environmental conditions. Organic-walled dinoflagellate cysts are very resistant to de-gradation within the sedi-ment, and are thus abundant in the sedimentary record. Since dinoflagellate species have different environmental preferences, they are valuable tools for paleo-environmental reconstructions to determine past sea-surface temperature, sea-surface salinity, primary productivity, eutrophication and sea-ice coverage.

However, since surface sediments are often deposited over many years, it is difficult to resolve year-to-year and seasonal changes in cyst ecology. Sediment traps provide an ideal tool to measure in situ cyst production and to determine the conditions under which they are produced. Analysis of 74 sediment trap samples was completed at UVic’s Paleoenviron-mental Laboratory and involved extensive microscopy work where dinoflagel-late cysts were identified and counted. Figure 1 shows a few of the diverse dinoflagellate taxa we found. Seasonal changes in dinoflagellate cyst production also occurred: during spring, summer and fall heterotrophic dinoflagellates were dominant, whereas autotrophic taxa increased production during win-ter. Seasonal variation in individual cyst taxa were related to changes in sea-surface temperature, salinity, and biogenic silica flux. Results through multi-variate statistical analysis using dinoflagellate cyst assemblages, environmental parameters and biogenic silica flux. confirm the observed seasonal trends. Results are being prepared for submission to a peer-reviewed journal. For more information contact Andrea Price (price@uvic.ca) or Dr. Vera Pospelova (vpospe@uvic.ca).

Figure 1. Top row: Motile stage dinoflagellates. Middle row- Cysts of heterotrophic dinoflagel-lates. Bottom Row: Cysts of autotrophic dinoflagellates. Scale bar is 10 mm.

Seasonal variation of phytoplankton production in Saanich inlet: A Sediment Trap Study

Andrea Price, BSc. Hons. School of Earth and Ocean Science University of Victoria

Awarded in 2007, the NSERC Major Re-sources Support grant has been the main funding source for the operational needs of VENUS. During these three years VENUS went from operating its first array in Saanich Inlet to the fully deployed network of the seafloor labs linking four distinct locations near Victoria and Vancouver. VENUS infra-structure will soon expand (seep Page 1,2) but current configuration includes:

• 2 Shore Stations that link seafloor instru-ments with the on-shore data archive;

• 3 seafloor Nodes that power seafloor arrays of equipment;

• 50km of fibre-optic cable that links all infrastructure into a high bandwidth network ;

• 50+ science instruments with 90+ sensors that continuously measure key ocean parameters and stream ocean data into the archive;

• Data Archive with 5.8TB of data and counting;

• Online Data Portal www.venus.uvic.ca – open for everyone to explore ocean data from VENUS.

VENUS Completes NSERC MRS Grant

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VENUS Data Delivery and Users 2007—2010(Q1)